Susceptibility testing is performed to determine the effectiveness of a substance to inhibit the growth or cause the death of a live substance, e.g., bacteria, fungi, etc. In some cases, the goal of susceptibility testing is to predict the success or failure of antibiotic or other drug therapy. Tests are performed in a test vessel to determine the growth or lack thereof of a particular microbe to various drug types, drug combinations, and/or drug concentrations. Susceptibility testing is generally performed under controlled conditions and may be used to identify the most effective drug type, combination, and/or dosage to treat an infection caused by a particular type of bacteria, for example.
Susceptibility testing for antibiotic testing can involve growing a secondary culture of bacteria from a primary culture obtained from a patient. Currently, culturing the bacteria involves many replication cycles before a measurable effect of the drug being tested can be detected. It is desirable to shorten the time required for susceptibility testing so that an appropriate therapy can be quickly delivered to a patient.